Polymetallic nodules cover vast areas of the ocean floor. They are more abundant in areas off the west coast of Mexico in the Pacific (known as the Clarion-Clipperton Fracture Zone), the Central Indian Ocean Basin, and the Peru basin. They are composed mainly of Mn, Fe, silicates and hydroxides. The trace metal contents such as Ni, Cu, Co and Mn and rare earth elements are attracting interest to mine these deposits to meet the growing demand for these metals. The nodules vary from micro-nodules to about 20 cm, the common size being two to eight centimeters.

Polymetallic nodules occur abundantly as 2D deposits at the unconsolidated sediment-water interface, while they could also be scantly buried in sediments at different layers. They occur in different sedimentary environments, shallow waters and lakes. The deposits of economic importance, however, occur mostly at 4,000-6,000 meters depths in areas of extremely low sedimentation rate. Nodules require a nucleus to start forming. This nucleus could be anything, varying from a piece of pumice, a shark tooth, an old nodule piece, basalt debris or even microfossils like radiolaria and foraminifera. The enrichment of metals around the nucleus takes place either hydrogenetically by the precipitation of metals from the seawater or through release from the interstitial spaces between the underlying sediments, by early digenetic process or by a combination of both. Nodules from the topographically smooth areas of the abyssal plain with an abundance of >5 kg/m2 and a combined >2 % grade (Cu, Ni and Co) form a sound economic proposition. They are found in about a dozen morphological types, such as spheroidal to discoidal.

A conference, “Ferromanganese deposits on the Ocean Floor,” organized at the Lamont – Doherty Geological Observatory in January 1972 and sponsored by the International Decade of Ocean Exploration, gave a considerable stimulus to the development of an incipient nodule mining industry.

Following the adoption of the Regulations on Prospecting and Exploration for Polymetallic Nodules in the Area, in July 2000, ISA entered into exploration contracts with seven contractors: the Government of India, Deep Ocean Resources Development Co. Ltd. (Japan), Institut français de recherche pour l’exploitation de la mer (France), JSC Yuzhmorgeologiya (Russia), China Ocean Mineral Resources Research and Development Association (China), Interoceanmetal Joint Organization and the Government of the Republic of Korea from 2001-2004. In addition, it entered into exploration contracts with 11 others after 2005: Federal Institute for Geosciences and Natural Resources (Germany), Nauru Ocean Resources Inc. (Nauru), Tonga Offshore Mining Limited (Tonga), Global Sea Mineral Resources NV (Belgium), UK Seabed Resources Ltd. (UK), Marawa Research and Exploration Ltd. (Kiribati), Ocean Mineral Singapore Pte. Ltd. (Singapore), UK Seabed Resources Ltd.-ll (UK), Cook Islands Investment Corporation (Cook Islands), China Minmetals Corporation (China) and Beijing Pioneer Hi-Tech Development Corporation (China).

Polymetallic nodules contractors

Contractor Contract Date Expiration Date Contract Extension Expiration Sponsoring State Location Contract [Note] Inspection and investigation
Interoceanmetal Joint Organization 29 Mar 2001 28 Mar 2016 28 Mar 2021 (1st)
28 Mar 2026 (2nd)
Bulgaria, Cuba, Czech Republic, Poland, Russian Federation and Slovakia Clarion-Clipperton Fracture Zone Public Info
JSC Yuzhmorgeologiya 29 Mar 2001 28 Mar 2016 28 Mar 2021 Russian Federation Clarion-Clipperton Fracture Zone
Government of the Republic of Korea 27 Apr 2001 26 Apr 2016

26 Apr 2021 (1st)

26 Apr 2026

(2nd)

Clarion-Clipperton Fracture Zone Public Info
China Ocean Mineral Resources Research and Development Association 22 May 2001 21 May 2016 21 May 2021 China Clarion-Clipperton Fracture Zone Public Info
Deep Ocean Resources Development Co. Ltd. 20 Jun 2001 19 Jun 2016 19 Jun 2021 (1st)
19 Jun 2026 (2nd)
Japan Clarion-Clipperton Fracture Zone Public Info
Institut français de recherche pour l’exploitation de la mer 20 Jun 2001 19 Jun 2016 19 Jun 2021 France Clarion-Clipperton Fracture Zone Public Info
Government of India 25 Mar 2002 24 Mar 2017 24 Mar 2022 (1st)
24 Mar 2027 (2nd)
Indian Ocean Public Info
Federal Institute for Geosciences and Natural Resources of Germany 19 Jul 2006 18 Jul 2021 18 Jul 2026 (1st) Germany Clarion-Clipperton Fracture Zone Public Info
Nauru Ocean Resources Inc. 22 Jul 2011 21 Jul 2026 Nauru Clarion-Clipperton Fracture Zone Public Info

Inspection report – Mining collector test –  Feb 2023

Investigation report – Overflow event – Apr 2023

Tonga Offshore Mining Limited 11 Jan 2012 10 Jan 2027 Tonga Clarion-Clipperton Fracture Zone Public Info
Global Sea Mineral Resources NV 14 Jan 2013 13 Jan 2028 Belgium Clarion-Clipperton Fracture Zone Public Info
UK Seabed Resources Ltd. 08 Feb 2013 07 Feb 2028 28 March 2031 United Kingdom of Great Britain and Northern Ireland Clarion-Clipperton Fracture Zone (I) Public Info
Marawa Research and Exploration Ltd. 19 Jan 2015 18 Jan 2030 Kiribati Clarion-Clipperton Fracture Zone Public Info
Ocean Mineral Singapore Pte Ltd. 22 Jan 2015 21 Jan 2030 Singapore Clarion-Clipperton Fracture Zone Public Info
UK Seabed Resources Ltd 29 Mar 2016 28 Mar 2031 United Kingdom of Great Britain and Northern Ireland Clarion-Clipperton Fracture Zone (II) Public Info
Cook Islands Investment Corporation 15 Jul 2016 14 Jul 2031 Cook Islands Clarion Clipperton Fracture Zone Public Info
China Minmetals Corporation 12 May 2017 11 May 2032 China Clarion Clipperton Fracture Zone Public Info
Beijing Pioneer Hi-Tech Development Corporation 18 Oct 2019 17 Oct 2034 China Western Pacific Ocean Public Info
Blue Minerals Jamaica Ltd 04 Apr 2021 03 Apr 2036 Jamaica Clarion-Clipperton Fracture Zone Public Info